Simple clojure server adapted from Clojure Cookbook that runs forever rather than exiting after reading the first line.

simple-server.clj

(ns hello.core
  (:require [clojure.java.io :as io])
  (:import [java.net ServerSocket]))

;; Server
(defn receive-msg [socket]
  (.readLine (io/reader socket)))

(defn send-msg [socket msg]
  (let [writer (io/writer socket)]
    (.write writer msg)
    (.flush writer)))

(defn server [port handler]
  (println "Starting server on port" port "with handler" handler)
  (with-open [server-sock (ServerSocket. port)]
    (doseq [sock (repeatedly #(.accept server-sock))]
      (with-open [sock sock]
        (send-msg sock (str "Ready..." \newline))
        (let [msg-in-seq (repeatedly #(receive-msg sock))
              msg-out (partial handler)]
          (doseq [line msg-in-seq 
                  :while (seq line)]
            (println "Recieved:" line)
            (send-msg sock (msg-out line)))
          (println "Disconnecting")
          (send-msg sock (str "Bye!" \newline)))))))

(defn test-server [] (server 8888 #(str (.toUpperCase %) \newline)))